1. Field of the Invention
This invention relates to an apparatus for cutting a coiled material sheet into trapezoidal pieces while continuously feeding the coiled material sheet at a fixed speed.
2. Brief Description of the Related Art
Trapezoidal sheet material cutting apparatuses are known in which vertically reciprocating blades cut through the entirety of the width of the material. Since the formation of trapezoid shaped pieces requires that the cut angles be different at opposite sides of each cut piece, it is necessary to adjust the angles of the blades between each cut. In the conventional trapezoid cutting apparatus, only the upper cutter is movable whereas the lower one is stationary. Moreover, the entire unit of cutter holders turns by an angle required for forming a trapezoid. This results in low cutting efficiency due to stoppage of the feeding of the material sheet following each cut in order to permit the angular adjustment of the cutter holders.